SN74LS85MELG ON Semiconductor, SN74LS85MELG Datasheet - Page 4

• Manufacturer Part Number: SN74LS85MELG
• Manufacturer: ON Semiconductor
• Type: Magnitude Comparatorr

Specifications of SN74LS85MELG

• Logic Family: LS
• Technology: Bipolar
• High Level Output Current: -400uA
• Low Level Output Current: 8mA
• Output Function: A<B, A=B, A>B
• Package Type: SO EIAJ
• Mounting: Surface Mount
• Pin Count: 16
• Polarity: Non-Inverting
• Abs. Propagation Delay Time: 45ns
• Operating Supply Voltage (typ): 5V
• Operating Supply Voltage (max): 5.25V
• Operating Supply Voltage (min): 4.75V
• Operating Temperature (max): 70C
• Operating Temperature (min): 0C
• Operating Temperature Classification: Commercial
• Number Of Bits: 4
• Lead Free Status / RoHS Status: Compliant

24-bit words with only two levels of device delay. With the
technique shown in Figure 1, six levels of device delay result
Figure 2 shows a high speed method of comparing two
A
B
L
4
4
I
I
I
A > B
A < B
A = B
A
A
5
0
A
A
WORD LENGTH
1
6
25 −120 Bits
A
A
7
2
5 −24 Bits
1 −4 Bits
A
A
8
3
#4
H
L
L
B
B
5
0
B
H
L
L
B
6
1
B
B
7
2
I
I
I
A > B
A < B
A = B
Table 1
O
O
O
B
B
A > B
A < B
A = B
A
A
8
3
I
I
I
0
0
A > B
A < B
A = B
A
A
0
0
A
A
A
1
1
A
1
NUMBER OF PKGS.
1
A
A
SN74LS85
NC
2
2
A
A
Figure 2. Comparison of Two 24-Bit Words
2
2
A
A
3
3
A
Figure 1. Comparing Two n-Bit Words
A
3
(LSB)
3
#5
B
B
B
0
0
B
8 −31
0
2 −6
0
B
B
1
B
A
B
B
1
1
L
9
9
1
1
B
B
B
B
2
2
2
2
O
O
O
O
O
O
B
B
A > B
A < B
A = B
B
B
A > B
A < B
A = B
MSB = MOST SIGNIFICANT BIT
LSB = LEAST SIGNIFICANT BIT
L = LOW LEVEL
H = HIGH LEVEL
NC = NO CONNECTION
3
3
I
I
I
3
3
http://onsemi.com
A
A > B
A < B
A = B
APPLICATIONS
A
10
0
A
A
L = LOW LEVEL
H = HIGH LEVEL
11
1
A
A
12
2
INPUTS
INPUTS
A
A
13
4
3
#3
B
B
10
0
A
B
when comparing two 24-bit words. The parallel technique
can be expanded to any number of bits, see Table 1.
19
19
NOTE:
The SN74LS85 can be used as a 5-bit comparator only
when the outputs are used to drive the A
inputs of another SN74LS85 as shown in Figure 2 in posi-
tions #1, 2, 3, and 4.
L
B
B
1
11
B
B
2
O
O
O
12
A > B
A < B
A = B
I
I
I
B
A > B
A < B
A = B
A
3
B
I
I
I
A
20
A > B
A < B
A = B
A
13
0
0
A
A
21
1
A
1
NC
A
A
I
I
I
A > B
A < B
A = B
A
22
2
A
SN74LS85
2
0
A
A
A
23
A
3
#1
1
3
B
B
A
20
B
0
A
B
2
0
14
14
B
B
L
21
1
A
B
3
#6
1
B
B
2
O
O
O
B
22
B
(MSB)
2
A > B
A < B
A = B
0
B
O
O
O
B
I
I
I
3
A > B
A < B
A = B
A < B
B
A > B
A = B
A
23
B
1
A
15
3
0
B
A
A
2
16
O
O
O
1
NC
B
A > B
A < B
A = B
3
A
A
17
2
A > B
A < B
A = B
0
−A
A
A
18
3
#2
3
B
B
and B
15
0
OUTPUTS
B
B
16
1
B
0
B
2
−B
O
O
O
17
A > B
A < B
A = B
B
3
3
B
18
NC